1. Field of the Invention
The present invention relates to a radiation image capturing system having a cassette including a radiation detector for detecting a radiation that has passed through a subject and converting the detected radiation into radiation image information, and an external controller for receiving the radiation image information transmitted from the cassette.
2. Description of the Related Art
In the medical field, there have widely been used radiation image capturing apparatus which apply a radiation to a subject and guide the radiation that has passed through the subject to a radiation detector, which captures a radiation image from the radiation. Known forms of the radiation detector include a conventional radiation film for recording a radiation image by way of exposure, and a stimulable phosphor panel for storing a radiation energy representing a radiation image in a phosphor and reproducing the radiation image as stimulated light by applying stimulating light to the phosphor. The radiation film with the recorded radiation image is supplied to a developing device to develop the radiation, or the stimulable phosphor panel is supplied to a reading device to read the radiation image as a visible image.
In the operating room or the like, it is necessary to read a recorded radiation image immediately from a radiation detector after the radiation image is captured for the purpose of quickly and appropriately treating the patient. As a radiation detector which meets such a requirement, there has been developed a radiation detector having a solid-state detector for converting a radiation directly into an electric signal or converting a radiation into visible light with a scintillator and then converting the visible light into an electric signal to read a detected radiation image.
Radiation image capturing systems with such a radiation detector are disclosed in Japanese Patent No. 3494683 and Japanese Laid-Open Patent Publication No. 2006-263339.
According to Japanese Patent No. 3494683, radiation image information detected by a radiation detector is transmitted to a processor by way of wireless communications, and is processed by the processor.
Japanese Laid-Open Patent Publication. No. 2006-263339 discloses an electronic cassette capable of transmitting radiation image information at high frequencies in excess of 1 GHz for high-speed transmission of a large amount of image data.
However, the electronic cassette consumes a large amount of electric power in transmitting radiation image. information to an external source by way of wireless communications. Therefore, a large-size battery is needed to energize the electronic cassette, and hence the electronic cassette becomes large in volume and weight.